Sha256: 6c94b6a25fbc2487bf9675b17003b8fe34810f41447bdcfd26e735a24b490889
Contents?: true
Size: 1.48 KB
Versions: 22
Compression:
Stored size: 1.48 KB
Contents
# Copyright 2021 Google LLC
#
# Use of this source code is governed by an MIT-style
# license that can be found in the LICENSE file or at
# https://opensource.org/licenses/MIT.
require "io/console"
require_relative "../config/environment"
require_relative "models/singer"
require_relative "models/album"
class Application
def self.run
# Get a random singer and then update the singer in a separate thread.
# This simulates a concurrent update of the same record by two different processes.
singer = Singer.all.sample
puts ""
puts "Singer #{singer.first_name} #{singer.last_name} with version #{singer.lock_version} loaded"
t = Thread.new do
# Load the singer in the separate thread into a separate variable.
singer2 = Singer.find singer.id
singer2.update last_name: "Rashford"
puts ""
puts "Updated the last name of the singer to #{singer2.last_name}"
end
t.join
# Now try to update the singer in the main thread. This will fail, as the lock_version number has been increased
# by the update in the separate thread.
begin
singer.update last_name: "Drake"
rescue ActiveRecord::StaleObjectError
puts ""
puts "Updating the singer in the main thread failed with a StaleObjectError"
end
singer.reload
puts "Reloaded singer data: #{singer.first_name} #{singer.last_name}, version: #{singer.lock_version}"
puts ""
puts "Press any key to end the application"
STDIN.getch
end
end
Application.run
Version data entries
22 entries across 22 versions & 1 rubygems